1. Field of the Invention
The invention relates to guides which improve performance of a Heidelberg press, and, in particular, to: 1) a snap-on drop away register guide which converts rectilinear movement of a plunger to oscillating movement of a retractable guide plate by virtue of a camming action therebetween; 2) a one-piece, snap-on raiser which cooperates with the drop away guide to quickly change the margin size of the paper to be printed and which also prevents improper mounting, thereof on the drop away guide; and 3) an adjustment device for a lock screw in an extension side guide which permits fine lateral adjustment of the side guide relative to the platen and is not required to be removed when not in use.
2. Description of the Prior Art
Conventional drop away register guides used in conjunction with a Heidelberg press result in several disadvantages among which are: 1) their guide plates do not consistently retract during the printing operation, thereby resulting in smashed type; 2) they do not accurately maintain the position of paper sheets on the platen and slip out of position due to high press speed and with sheets of paper having certain size and/or weight; 3) the procedure for mounting and demounting them from a guide bar is time consuming due to the use of pins or screws; and 4) their guide plates during printing retract relatively prematurely, thereby do not provide for guidance of the paper during the period guidance is most desired.
In bleed printing, whenever it is desired to change the lower margin height on the paper, such as when printing business cards or other stocks of similar small size, it is common to substitute "nickel" guides for "brass" guides on the guide bar. This procedure, however, is a time consuming operation wherein unfastening and removal of the brass guides from the guide bar, and mounting and fastening of the nickel guides in the proper position are required.
Another conventional device which effects a change in margin height, is a raiser which is detachably mounted, by screws or the like, to the housing of a drop away register guide of the type described above. Difficulties arise with the use of these types of raisers because the mounting and demounting thereof are time consuming. Other devices used for adjusting margin height are rather complicated devices which include springs and pins. Thusly, as believed apparent, prior art techniques and devices for changing the height of the paper margin can be characterized as being relatively complicated, cumbersome and expensive.
Conventional side extension guides used in conjunction with a Heidelberg press are not laterally adjustable and therefore do not permit sideways registering without changing the form. Additionally, inconveniences arise in the use of conventional extension side guides because the register could be hampered on a normal size sheet that hits two side guides. Thusly, these side guides have to be removed at the end of a small paper run. This removal process requires expenditure of much time and attention. Furthermore, as is often the case, conventional side guides when removed drop and become lost in the platen well.